French wild-card entry Lois Boisson upset sixth-ranked Mirra Andreeva 7-6 (6), 6-3 on Wednesday in front of a boisterous and largely partisan crowd at Roland-Garros to reach the semifinals of the French Open. Andreeva repeatedly showed her frustration with the crowd as excited fans chanted “Lois, Lois” between points, waved Tricolour flags, shouted during play and even applauded the Russian teenager’s errors.

The 22-year-old Boisson became the first woman to reach the semifinals at her debut Grand Slam tournament since 1989 when Monica Seles and Jennifer Capriati both did it at the French Open. She is also the youngest French semifinalist at a Grand Slam event since Amelie Mauresmo at Wimbledon in 1999.

The first set was marked by momentum swings and brilliant shot-making from both players. Boisson twice found herself down a break but fought back each time, using heavy spin and deep groundstrokes to trouble her Russian opponent. Andreeva grew visibly tense on key points, struggling to maintain her composure and wasting a chance to close out the set when up 5-3. Despite saving three set points and forcing a tiebreaker, she ultimately handed the set to Boisson with two consecutive backhand errors.

Andreeva responded strongly at the start of the second set, racing to a 3-0 lead. But Boisson broke back with a thunderous backhand winner down the line, drawing a roar of approval from the lively crowd. Andreeva received a warning after netting a routine forehand volley and angrily hitting a ball into the stands. She then argued with the umpire over a call that gave Boisson a break point. On the very next point, Andreeva double-faulted and never recovered.